This article basically explains that the user experience work does not apply only to public facing tools/websites/applications. And for the applications behind the firewall, it's not that different even if this concern is maybe newer in this domain and some specific issues might arise like the cultural clash between the IT people and the design people or the lack of detailed usage data.
I was also very pleased to read the following sentences in this article:
If we want applications with great UX, whether public-facing or for internal consumption, then we need developers who value the importance of UX and have the skills to deliver it. It’s the development teams that take on the UX role after we’re gone, so their buy-in and ability is crucial to ongoing success.
That's pretty obvious to me but still, in my experience, very underevaluated. I would even add that a developer who values the importance of UX might also have ideas on this topic and he's not necessarily only interested in his black terminal and the code he writes in it…